1. Field of the Invention
The present invention relates to solders and to soldered articles.
2. Description of the Related Art
Solders are conventionally used to electrically or mechanically connect electronic devices and electronic parts. As such solders, a solder mainly containing Sn and Pb (hereinafter referred to as “Sn—Pb solder”) has been generally employed. In consideration of global environment, however, solders mainly including Sn and containing, for example, Ag, Bi, Cu, In, or Sb as balance and containing no lead (Pb) (hereinafter referred to as “Pb free solder”) have been in use. Soldered articles having electrical joints with satisfactory solderability are produced by using these Pb free solders.
However, soldered articles using solders mainly containing Sn, particularly those using Pb free solders invite electrode leaching upon soldering. In addition, Sn diffuses into an electrode (conductor) when the articles are left at high temperatures or are subjected to heat aging, to thereby deteriorate electrical characteristics and mechanical characteristics of the resulting electronic devices and electronic parts.